function split(val) {
    return val.split(/\s/);
}
function extractLast(term) {
    return split(term).pop();
}

$(function () {   
    $(".tag-search").autocomplete({
        source: function(request, response) {
                $.ajax({
                 url: "http://hestia.atc.gr/epart/tags.php",
                 dataType: 'jsonp',
                 data: {term: extractLast(request.term) },
                 success: response
               });
        },
        search: function() {
                // custom minLength
                var term = extractLast(this.value);
                if (term.length < 1) {
                    return false;
                }
                return true;
        },
        focus: function() {
            // prevent value inserted on focus
            return false;
        },
        select: function(event, ui) {
            var terms = split(this.value);
            // remove the current input
            terms.pop();
            // add the selected item
            terms.push( ui.item.value );
            // add placeholder to get the comma-and-space at the end
            terms.push("");
            this.value = terms.join(" ");
            return false;
        }});
});